Transcript m5zn_65570b1ef808776

An Introduction to Environmental
Science
UNIT 1
What is our environment?
• Environment: is everything that affects a living
organism.
• The environment includes:
• Biotic factors - living things
• Examples: Animals, plants, forests, fungi, etc.
• Abiotic factors - nonliving things
• Examples: Continents, oceans, clouds, soil, rocks
Environmental Science
• Environmental Science –
• the study of the air, water, and land
surrounding an organism or a
community, which ranges from a small
area to Earth’s entire biosphere.
Environmental science is defined as
the interaction of humans with the
environment.
Fields of Environmental Science
• Environmental science is an
interdisciplinary science, which
means that it involves many
fields of study
• Important to the foundation of
environmental science is ecology
• Ecology - the study of
interactions of living organisms
with one another and with their
environment
Environmental science is not
environmentalism
• Environmental science
• The pursuit of knowledge
about the natural world
• Scientists try to remain
objective
• Environmentalism
• A social movement dedicated
to protecting the natural world
The Goals of Environmental Science
• A major goal of environmental science is to
understand and solve environmental problems.
• To accomplish this goal, environmental scientists
study two main types of interactions between
humans and their environment:
• How our actions alter our environment
• The use of natural resources
1) Humans and the world around us
• We depend completely on the environment for
survival
• Increased wealth, health, mobility, leisure time
• Natural systems have been degraded
• Ex: pollution, erosion and species extinction
• Environmental changes threaten long-term
health and survival
2) The use of natural resources
• Natural resources - substances and energy sources
needed and vital for survival
• Renewable resources:
• Always available: sunlight, wind, wave energy
• Renew themselves over short periods: timber,
water, soil
• These can be destroyed
• Nonrenewable resources:
• Can be depleted
• Oil, coal, minerals
Renewable Resources
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Sustainable yield
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Highest rate at which a potentially renewable resource
can be used without reducing its available supply
throughout the world or in a particular area.
Environmental Degradation
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Depletion or destruction of a potentially renewable
resource such as soil, grassland, forest, or wildlife that
is used faster than it is naturally replenished. If such
use continues, the resource becomes nonrenewable
(on a human time scale) or nonexistent (extinct).
Non-Renewable Resources
Resource that exists in a fixed amount (stock) in various
places in the earth's crust and has the potential for
renewal by geological, physical, and chemical processes
taking place over hundreds of millions to billions of years
such as:
 Energy, metals, and other minerals
Examples are copper, aluminum, iron, salt, clay, coal,
and oil.
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Any potentially renewable resource can become nonrenewable if used improperly

Theoretically, never exhaust due to economic feasibility
for extracting.
Non-renewable resources and natural
capital degradation
Extracting, processing and use come at
an environmental expense
Environmental science… can help us avoid
mistakes made by past civilizations.
Understand how the natural world works
 Understand how human and natural systems interact
 Accurately assess the status and trends of crucial
natural ecosystems
 Establish long-term sustainable relationships with the
natural world
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What is an “environmental problem”?
• The perception of what constitutes a
problem varies between individuals
and societies
• Ex: DDT, a pesticide
• In developing countries: welcome
because it kills malaria-carrying
mosquitoes
• In developed countries: not
welcome, due to health risks
• Environmental problems generally
involve pollution, resource depletion,
loss of biodiversity
Tragedy of the Commons
• Unregulated exploitation leads to resource
depletion
• Soil, air, water
• Resource users are tempted to increase use until
the resource is gone
• Solution?
• Private ownership?
• Voluntary organization to enforce responsible use?
• Governmental regulations?
The “ecological footprint”
• The environmental impact of a
person or population
• Amount of biologically
productive land + water
• for raw materials and to
dispose/recycle waste
• Overshoot: humans have
surpassed the Earth’s capacity
We are using 30% more of the planet’s resources than are available on a
sustainable basis!
Ecological footprints are not all equal
• The ecological footprints of
countries vary greatly
• The U.S. footprint is almost 5
times greater than the world’s
average
• Developing countries have
much smaller footprints than
developed countries
Population & consumption
• Human population growth exacerbates all
environmental problems
• The growth rate has slowed, but we still add more than
200,000 people to the planet each day
• Our consumption of resources has risen even faster
than our population growth.
• Life has become more pleasant for us so far
• However, rising consumption amplifies the demands we make
on our environment.
Global human population growth
• More than 6.7 billion
humans
• Why so many humans?
• Agricultural revolution
• Stable food supplies
• Industrial revolution
• Urbanized society
powered by fossil fuels
• Sanitation and medicines
• More food
We face challenges in agriculture
• Expanded food production led to increased
population and consumption
• It’s one of humanity’s greatest achievements, but
at an enormous environmental cost
• Nearly half of the planet’s land surface is used
for agriculture
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Chemical fertilizers
Pesticides
Erosion
Changed natural systems
We face challenges in pollution
• Waste products and artificial chemicals used in
farms, industries, and households
Each year, millions of people die from pollution
We face challenges in climate
• Scientists have firmly concluded that humans are
changing the composition of the atmosphere
• The Earth’s surface is warming
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Melting glaciers
Rising sea levels
Impacted wildlife and crops
Increasingly destructive weather
Since the Industrial Revolution, atmospheric carbon dioxide
concentrations have risen by 37%, to the highest level in
650,000 years
We face challenges in biodiversity
• Human actions have driven many species extinct, and
biodiversity is declining dramatically
• We are at the onset of a mass extinction event
Biodiversity loss may be our biggest environmental
problem; once a species is extinct, it is gone forever
Our energy choices will affect our
future
• The lives we live today are due to fossil fuels
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Machines
Chemicals
Transportation
Products
• Fossil fuels are a one-time bonanza; supplies will
certainly decline
We have used up ½ of the world’s oil supplies; how will we
handle this imminent fossil fuel shortage?
Sustainable solutions exist
We must develop solutions that protect both our quality
of life and the environment:
1. Organic agriculture
2. Technology
•
Reduces pollution
3. Biodiversity
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Protect species
4. Waste disposal
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Recycling
5. Alternative fuels
Sustainability: a goal for the future
• How can humans live within the planet’s means?
• Humans cannot exist without functioning natural systems
• Sustainability
• Leaves future generations with a rich and full Earth
• Conserves the Earth’s natural resources
• Maintains fully functioning ecological systems
• Sustainable development: the use of resources to
satisfy current needs without compromising future
availability of resources
Will we develop in a sustainable way?
• The triple bottom line: sustainable
solutions that meet
• Environmental goals
• Economic goals
• Social goals
• Requires that humans apply
knowledge from the sciences to
• Limit environmental impacts
• Maintain functioning ecological
systems
The Nature of Science
• Science:
• A systematic process for learning about the
world and testing our understanding of it
• A dynamic process of observation, testing,
and discovery
• The accumulated body of knowledge that
results from this process
• Science is essential
• To sort fact from fiction
• Develop solutions to the problems we face
Applications of science
1. Policy decisions and
management practices
2. Technology
Energy-efficient methanol-powered fuel cell car
from DaimlerChrysler
Restoration of forest ecosystems altered by
human suppression of fire
Conclusion
• Environmental science helps us understand our
relationship with the environment and informs our
attempts to solve and prevent problems.
• Identifying a problem is the first step in solving it
• Solving environmental problems can move us towards
health, longevity, peace and prosperity
• Environmental science can help us find balanced solutions to
environmental problems